Fasting Guides / Hydration & Supplements
Sodium During Fasting
Why sodium is the most critical electrolyte to address during fasting and how to get enough without breaking your fast.
Why You Lose More Sodium
Insulin's effects on the kidneys include telling them to retain sodium. When you fast and insulin falls, this signal disappears — and the kidneys excrete sodium at a higher rate. This is not a problem with your kidneys. It is normal physiology, but it requires active management.
How Much Do You Need?
The general population is often told to limit sodium, but fasters frequently need more than the standard recommendation. Aim for at least 2,000–3,000mg of sodium per day during regular intermittent fasting. If you are doing extended fasting (24+ hours), you may need more. How do you know if you are getting enough? The absence of headaches, dizziness, and muscle cramps is a reliable indicator.
Best Fasting-Compatible Sources
Plain sea salt or Himalayan pink salt dissolved in water is the simplest approach. Add a pinch to your morning water. Zero-calorie electrolyte powders containing sodium are another option — read the label to confirm they are sugar-free. Broth (unseasoned bone broth or vegetable broth) is a popular choice for extended fasters — it contains sodium and is deeply satisfying while technically breaking a strict fast for some protocols.
What to Avoid
Sports drinks contain sugar and are not appropriate for maintaining a fast. Many commercial electrolyte tablets contain sweeteners, fillers, or artificial coloring — check the ingredient list if you are being strict. Table salt works as well as specialty salts — the marketing around Himalayan pink salt is largely overblown, but it tastes slightly different and both are fine.